The invention relates to a method of operating an appliance. The invention further relates to an appliance capable of performing the above method.
The steady increase in complexity of modern home electronic appliances confronts users of such an appliance with the problem of learning its functions, and in which circumstances these functions can be invoked. Traditionally, electronic appliances are controlled by buttons on the appliance itself or on a remote control of the appliance. As the number of functions grows, the number of buttons tends to increase as well, which severely reduces the usability of the appliance. Often, multiple functions are operated by means of a single button, thus requiring, for example, the user to press the button multiple times, account for a time out, or press a xe2x80x98shiftxe2x80x99 button simultaneously. As a consequence, a button has a different effect in different situations, or has only effect in one situation while being ineffective in another situation. This is confusing to the user, especially when he is not yet familiar with the appliance.
Graphical user interfaces for controlling appliances can remedy these problems to a certain extent but cause new problems, such as complicated menu systems or an abundance of graphical information. Graphical user interfaces may be designed to show only a limited number of options at a time, to facilitate the operation of the appliance. For example, U.S. Pat. No. 5,648,824 discloses a television receiver capable of displaying a graphical representation of a multi-direction actuation pad of the remote control. Labels representative of functions of the appliance are located near or within the graphical representation, so as to indicate that said functions can be activated by pressing the corresponding part of the actuation pad on the remote control. A problem of such an approach is that the user has only a very limited view on the appliance""s functionality.
It is an object of the invention to provide an improved method and appliance of the type defined in the opening paragraph, having an easy user interface for controlling the appliance. To that end, a method according to the invention is provided, comprising a step of displaying a state diagram on a display screen, the state diagram comprising state symbols representing operative states of the appliance, a step of displaying a state cursor indicating a position relative to the state diagram, a step of user operably moving, in response to at least one user supplied command indicating a motion direction, the state cursor to a state symbol representing a desired state of the appliance, and a step of bringing the appliance into the desired state in response to said movement. In this way it is achieved that the user is enabled to control the appliance by simply moving the state cursor to a state symbol which represents a desired state of the application. It is further achieved that the user has a comprehensible overview of the appliance""s functions. A state is regarded as a user discernable mode of the appliance, for example dedicated to a specific function. In a video recorder (VCR) one may discern a play state, a pause state, a record state etc. In a TV one may discern a TV mode, a VCR mode, a teletext mode, etc. A state symbol may be a simple shape, e.g. a rectangle, bearing a text label indicating the represented state, or a graphical icon representative of said state. A state symbol may also comprise only a text label. The state cursor may, for example, be a pointer or involve emphasizing the state symbol where the state cursor is located, e.g. by means of a differently colored edge, highlighting the entire state symbol, or an additional marker within or near the state symbol. Moving the state cursor to a new state symbol causes the appliance to adopt the state represented by the new state symbol. The user directs the state cursor through the state diagram by issuing commands representing a motion direction, for example, the four directions up, down, left and right. Moving the state cursor may be accomplished by any suitable means, such as arrow buttons on a remote control, a tracker ball, computer mouse, etc.
An embodiment of the method according to the invention is characterized by the method further comprising a step of displaying transition indications for indicating permissible transitions between said operative states, the movement of the state cursor being restricted to proceed in accordance with said permissible transitions. In this way it is achieved that the user cannot erroneously move the state cursor to a state to which there is no permissible transition, thus avoiding unnecessary error messages from the appliance, or avoiding that the appliance does not respond at all. It is further achieved that the user has a comprehensible overview of which functions can be invoked in different situations A permissible transition between states may, for example, be indicated by means of a line or arrow pointing from one state symbol to another state symbol, thus indicating the direction of the permissible transition. Alternatively, a permissible transition may be indicated by state symbols having a common edge or partially overlapping each other. In response to a user command corresponding to a non-permissible direction, the state cursor remains at its current location or moves to a default location or a location which is determined by guessing the user""s intention.
An embodiment of the method according to the invention is characterized by the method further comprising a step of displaying a neutral state symbol not representing an operative state of the appliance, a movement of the state cursor to said neutral state symbol having a neutral effect on the operation of the appliance. Such a neutral state symbol can be applied if movement of the state cursor should not cause a state change of the controlled appliance. For example, if the appliance is capable of performing various functions simultaneously, a neutral state symbol can be used to relocate the state cursor while activating or deactivating such functions.
An embodiment of the method according to the invention is characterized by the method further comprising a step of moving the state cursor relative to a state symbol without affecting the current state of the appliance, so as to select a respective state transition related to said state symbol. This embodiment is advantageous if the number of permissible state transitions is higher than the number of moving direction which can be controlled, or if the layout allows multiple transitions in the same direction. For example, if multiple arrows representing state transitions leave a state symbol in an upward direction, the user may select a starting point of the desired transition by, for example, moving left or right, before actually performing the transition. This selection does not affect the state of the appliance, which is visualized by the current state indicator remaining at the same state symbol.
An embodiment of the method according to the invention is characterized by the method further comprising a step of displaying at least one current state indicator marking a respective state symbol as representing a current state of the appliance. It is thus achieved that the current state of the controlled appliance is communicated to the user in a comprehensible way. If multiple functions of the appliance can be performed simultaneously and independently, e.g. playing and recording in a hard-disk based video recorder, multiple current state indicators may be displayed, indicating the state of said functions. The current state indicator marking a state symbol as representing a current state of the appliance may, for example, involve a differently colored edge, highlighting the entire state symbol, or an additional marker within or near the state symbol.
An embodiment of the method according to the invention is characterized by the method further comprising a step of expanding a state symbol, in response to a movement of the state cursor to said state symbol, to display further state symbols representing subordinate states of a state represented by said state symbol. The operation of many appliances can be defined by a hierarchy of states, where a state may have subordinate states which are only relevant within the context of said state. For example, in a consumer audio/video system, a number of states are discernable at a top level including, for example, a TV mode, a VCR mode, a teletext mode etc. Within a VCR mode, subordinate states are discernable, such as a stop state, a play state, a pause state etc. A state symbol representing such a state having subordinate states may comprise nested state symbols representing the subordinate states. Preferably, a state symbol is expanded in response to a movement of the state cursor to the state symbol. Consequently, as soon as a state becomes the current state, its subordinate states of the appliance become visible in the state diagram and the user is enabled to activate any of these subordinate states. Alternatively, the expansion may be performed in response to an explicit user command, for example, by means of a dedicated button on the remote control.
An embodiment of the method according to the invention is characterized by the method further comprising a step of collapsing said state symbol to hide said further state symbols in response to a movement of the state cursor away from said state symbol. Hence, when a state ceases to be the current state, its related state symbol ceases to show symbols representing subordinate states. Alternatively, the collapse may be performed by an explicit user command.
The invention is particularly suitable for consumer electronic appliance, since it provides an easy to learn and consistent user interface, and thereby provides the user with a comprehensible overview of the appliance""s functionality.